Professor Ned Brainard of Medfield College is so engrossed in a scientific experiment he fails to show up for the third time for his wedding with pretty Betsy Carlisle. But though he loses his girl to rival Professor Shelby Ashton, his absentmindedness pays off with the creation of Flubber, a rubbery substance with an antigravity agent. With his new invention he is able to help the puny Medfield basketball team win against Rutland College; prevent a crook, Alonzo Hawk, from stealing Flubber; and win back Betsy, flying in a Flubber-ized Model T to Washington to give the powerful creation to a grateful government.